Forward impulse response "FIR" digital filters are, in general, well known in the art of digital communications. FIR linear-phase matched filters are desirable in such art. FIR linear-phase matched filters can be designed to have both constant phase delay and constant group delay, which results in excellent distortion characteristics of such filters.
However, the design of FIR linear-phase matched filters to meet specific performance objectives is generally more difficult than the design of infinite impulse response filters for similar applications. In addition, such FIR filters implemented with recursive techniques can be subject to instability problems, such as limit-cycle oscillations.
Thus, it would be desirable to have a filter, and a design technique for such a filter, which is relatively simple, and which will approximate FIR linear-phase matched filters with little degradation in performance and freedom from distortion, while still providing significant savings in hardware.